The presently disclosed and claimed inventive concept(s) relate to a composition and method designed for Front End Of Line (FEOL) semiconductor processing of substrates comprising aluminum (Al), and, more particularly, to post-etch residue removal with compositions which not only remove undesirable post etch-residues, but also simultaneously passivate exposed Al surfaces.
In fabricating integrated circuits, liquid chemical compositions have been designed for use in wafer cleaning to remove undesirable particles and processing residues from the wafer, i.e., substrate, surface and thereby prepare the wafer surface for subsequent processing steps. During wet cleaning, the particles and residues must be removed without altering the properties of the underlying substrate surface. In FEOL cleaning processes, the substrate materials are typically silicon, silicon oxides and silicon nitrides, which are robust enough to withstand relatively harsh thermal and chemical operations, and, thus, conventional wet cleaning methods have tended to employ various mixtures of inorganic acids or ammonia with hydrogen peroxide. Recent semiconductor designs have been replacing poly-silicon gates with metals coupled with implementation of high-k dielectrics. The new FEOL substrates are not able to withstand convention aggressive cleaning. Beyond that, the tolerance for substrate material loss has been getting smaller as device size has been shrinking.
Thus, the need exits for improved compositions and methods for post-etch residue removal that are compatible with new materials being used in FEOL processing, including Al, TiN, TaN, NiSi and silicon oxide. It is particularly important for such improved compositions to be designed with functionalities that will simultaneously condition, e.g., passivate, the Al metal surface and thereby protect it from degrading between device processing steps.